San Francisco 49ers quarterback Colin Kaepernick takes part in drill before facing the Denver Broncos in an NFL football scrimmage at the Broncos' headquarters Wednesday, Aug. 26, 2015, in Englewood, Colo. (AP Photo/David Zalubowski) less

San Francisco 49ers quarterback Colin Kaepernick takes part in drill before facing the Denver Broncos in an NFL football scrimmage at the Broncos' headquarters Wednesday, Aug. 26, 2015, in Englewood, Colo. (AP ... more

Photo: David Zalubowski, Associated Press

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49ers’ defensive coordinator Eric Mangini has had a good amount of success against Peyton Manning.

49ers’ defensive coordinator Eric Mangini has had a good amount of success against Peyton Manning.

Photo: David Zalubowski, Associated Press

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49ers’ Eric Mangini has had success against Peyton Manning

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CENTENNIAL, Colo. — During his 17-year NFL career, 49ers defensive coordinator Eric Mangini has learned plenty from his mentors, Hall of Fame head coach Bill Parcells and New England head coach Bill Belichick, a winner of four Super Bowls.

However, another person who has made Mangini a better coach has blown up the NFL record book, but hasn’t blown a whistle. His name: Peyton Williams Manning.

Mangini and the Broncos’ quarterback were on the same field again Wednesday for the first of two joint practices between the 49ers and Broncos. And they didn’t need an introduction.

Mangini, 44, has helped game-plan against Manning, 39, as a defensive assistant or a head coach 14 times since Manning joined the league in 1998. For Mangini, the countless hours spent poring over video of Manning in advance of those meetings has provided an education.

“Oh, yeah, he’s made me a better coach,” Mangini said. “You have to be. If there’s a weakness in your scheme, he’s going to find it. If there’s a problem that you have and you think you have it fixed, he’s going to test to make sure that’s accurate. If there’s a person that he can exploit, he’s going to find him.”

It’s debatable how beneficial two joint practices will be, but Mangini is pleased they are coming against Manning, who posted a 157.2 passer rating and broke Brett Favre’s record for career touchdown passes in a 42-17 romp over the 49ers in October.

Said safety Eric Reid after Manning’s surgical performance: “I’m not sure what their coaches do, but they probably don’t have to do much. … You’re playing against a coordinator when you’re out there.”

This week, the 49ers get to face Manning without the specter of being humiliated in prime time. And the four hours of practice time should provide a few lessons for a nine-man cornerback corps that includes seven players 24 or younger (the corners have combined to play in 143 games, 113 fewer than Manning). In addition, the back-to-back sessions will allow Mangini to get a better handle on the system he installed in the offseason.

“To me, in going against him, it’s more ‘Are we sound?’” Mangini said. “‘Where are we not sound? What the areas he sees out here that he thinks he can get after?’”

On Wednesday, Manning threw one interception in team drills and it came courtesy of safety Antoine Bethea, 31, who spent his first six seasons as Manning’s teammate in Indianapolis.

Bethea, a sixth-round pick from Howard University, gives Manning plenty of credit for a career that has included three Pro Bowls. During his days in Indianapolis, he said, he thought his toughest challenge came in the days before kickoff.

“In games, he just made it so easy,” Bethea said. “Going up against one of the best quarterbacks in practice — when game time comes, the game slows down. So he helped me out a lot, even if he doesn’t know it.”

Mangini shares the sentiment. He was a 27-year-old Jets assistant when New York walloped Indianapolis 44-6 in the third game of Manning’s 256-game career. The 22-year-old quarterback threw two interceptions and posted his second-lowest passer rating (39.3).

Two months later, however, the kid quarterback exacted his payback. Manning erased a 13-point, second-half deficit with two touchdown passes in the final 16 minutes of a 24-23 win over the Jets.

“He got us on two hard-sell, play-action shots that changed the whole complexion of the game,” Mangini said Wednesday, 17 years later. “… It’s not like you’re ever going to go through a game and he doesn’t get you. It’s just how many times he’s going to get you.”

Mangini’s teams have actually gotten Manning quite a bit over the years. Including playoff games, Mangini has an 8-6 record against Manning as a defensive assistant or head coach (Manning went 1-7 against New England when Mangini was the Patriots’ secondary coach, 2000-04).

“They’ve always been a well-coached bunch, always been really sound in their schemes, and he’s had good players in the places that I have played him against,” Manning said of Mangini. “So I’ve always thought it has been a challenge going against his defenses.”

For his part, Mangini said he has enjoyed scheming against Manning — “I don’t know if the word is ‘fun’ exactly,” Mangini said, smiling. He understands that he might not have another chance after Saturday’s night preseason meeting.

Manning, after all, could be embarking on his final season, and the 49ers won’t meet the Broncos in the regular season. Mangini and Manning aren’t buddies, but they have had a few casual conversations over the years. And the coach plans to have at least one more chat with the quarterback before the 49ers leave Colorado.

“I hope to talk to him here and just reiterate how much I respect him,” Mangini said. “He makes you a better coach.”